| 摘要 |
1305079 Automatic control LANDIS & GYR AG 18 Sept 1970 [28 Oct 1969] 44664/70 Heading G3R A PID controller comprises a P1 subsidiary controller, an amplifier connected between a delayed differentiator and the subsidiary controller, the amplification factor being variable, and the delay device of the delayed differentiator and the integrator of the P1 subsidiary controller having fixed time constants. In Fig.4, a measured value X of a variable is compared with a desired value W so that any error E is applied both directly and through the differentiator 2 and amplifier 3 to the proportional and integral controller 1 to restore the variable to the desired value. The differentiator functions by applying the error directly and through a delay unit 6 in opposite senses to the input of amplifier 3. Suitable proportional band and time constants are set for the proportional, integral and differential sections and a response suited to the control of e.g. a heating and ventilating system, is then obtained by adjustment of the gain of amplifier 3 which may be positive or negative. |
